How can I pre-select a dropdown option using previously submitted data from database, MySQLI

问题

I have two tables: orders and companies. Note that both tables has a company_id row.

Orders Table:
order_id | order_name | company_id | .....

Companies Table:
company_id | company_name | .....

I have a page with a form that INSERTS data for an order into the orders table in my database. Part of the order is selecting a company from the companies table to go with it, so I use a dropdown for this.

I also have another page with a form that UPDATES that data (an edit page). When I click on the button to bring up the edit page, I'd like to have the previously submitted data in the input fields. With text fields, I just use value="<?php echo $company['whatever']; ?>". However, with dropdown menu's I can't figure out how to pre-select the correct option.

Here is my URL structure:

http://website.com/orders.php?page=edit&order_id=1

Here is what I have to create my dropdown menu:

$getOrder   = mysqli_query($db, "SELECT * FROM orders WHERE order_id = ".$_GET['order_id']);
$getCompany = mysqli_query($db, "SELECT * FROM companies ORDER BY company_name ASC");

....

<select class="form-control" name="company_id" id="company_id">
<?php
    if($getCompany) {
        while($company = mysqli_fetch_assoc($getCompany)) { ?>
            <option value="<?php echo $company['company_id']; ?>">
                <?php echo $company['company_name']; ?>
            </option>
        <?php }
    } 
?>

How can I get selected on the option that's been previously selected?

回答1:

If $getOrder has the order details (including company_id), and $getCompany has the company details (including company_id), then you can compare the two.

If they are equal, echo out selected as an attribute in the option, like so:

<select class="form-control" name="company_id" id="company_id">
<?php
    if($getCompany) {

        //Get company ID from Order
        $orderID = $getOrder["company_id"];

        while($company = mysqli_fetch_assoc($getCompany)) { ?>
            <option value="<?php echo $company['company_id']; ?>"
            <?php 
                //Compare and echo `selected` if they are equal
                if($orderId==$company["company_id"]) echo "selected";
            ?>>
                <?php echo $company['company_name']; ?>
            </option>
        <?php }
    } 
?>

That code can be cleaned up, however:

<select class="form-control" name="company_id" id="company_id">
<?php
    if($getCompany) {
        $orderID = $getOrder["company_id"];
        while($company = mysqli_fetch_assoc($getCompany)) {
            echo "<option value='{$company['company_id']}".($getOrder["company_id"]==$getCompany["company_id"] ? " selected" : null).">{$company['company_name']}</option>";
        }
    } 
?>

来源：https://stackoverflow.com/questions/35607477/how-can-i-pre-select-a-dropdown-option-using-previously-submitted-data-from-data

标签

php

database

mysqli